A technology of integrating a metal alloy material and a resin material, which are heterogeneous materials, using an adhesive has been used in various fields such as automobiles, electronic products, industrial equipment, and the like, but in a method using the adhesive, there are problems in that precise bonding is difficult, a curing time is long, and maintenance and management of a state of the adhesive is difficult.
For these reasons, according to the related art, methods of bonding the metal alloy material and the resin material, which are heterogeneous materials, without using an adhesive, have been studied. As one of the methods, a nano method has been actively studied.
A technology of bonding heterogeneous materials using the nano method, which is a technology of forming a groove in a surface of a metal alloy material at a nano size to insert a resin material thereinto, has an advantage in that tensile force is higher than in a case of using an adhesive.
However, when the metal-resin complex is exposed to a harsh environment, bonding strength of the metal-resin complex is not sufficient, such that a metal-resin complex having more excellent bonding strength should be developed.